The present disclosure relates to the field of electronic technology, and particularly, to an enable signal generation circuit, a power conversion circuit, and a display device.
Conventionally, Enable Control pins and Single Wire Protocol pins are typically provided in a DC-DC power supply chip with adjustable output voltage. When a signal on the enable control pin is valid, an input voltage is input to the DC-DC power supply chip and an output voltage of the DC-DC power supply chip is controlled according to the number of pulses included in a signal on the single wire protocol pin.
In an Active-Matrix Organic Light-Emitting Diode (AMOLED) display device, the DC-DC power supply chip is used in cooperation with a source electrode drive chip. The output voltage of the DC-DC power supply chip is used to drive the light-emitting element. The source electrode drive chip is used to output a signal on the single wire protocol pin to the DC-DC power supply chip to control the output voltage value of the DC-DC power supply chip, so as to control the light-emitting intensity of the light-emitting element.
When the display device stars up, bias voltages are applied to the source electrode drive chip and the DC-DC power supply chip at the same time, and the signal on the single wire protocol pin is delayed in time by 10 to 30 milliseconds, compared to the input voltage of the DC-DC power supply chip. In addition, when the display device stars up, the expected starting up timing sequence is that: when opening the device, the output voltage of the DC-DC power supply chip at the output terminal has a default value, which is less than the operating voltage of the light-emitting element, and at the time the light-emitting element enters the critical point of being lightened; thereafter, the signal on the single wire protocol pin outputted from the source electrode drive chip is input to the DC-DC power supply chip to control the DC-DC power supply chip to generate the operating voltage required for the light-emitting element. Previously, there are cases where the signal on the single wire protocol pin is input to the DC-DC power supply chip prior to the input voltage, and the accomplishment of the above timing sequence cannot be ensured. In these cases, the inside of the DC-DC power supply chip may be impacted by a large current, which will make the current limiting circuit act and enter into a protection mode, causing the DC-DC power supply chip unable to start.